Google has agreed to refund at least $19 million to settle charges that it unfairly billed parents for purchases that their kids made while playing video games such as Ice Age Village and Air Penguins on mobile devices. Children sometimes put hundreds of dollars on their parents' credit cards without permission, the Federal Trade Commission said Thursday in announcing the settlement. In Air Penguins, for example, children can buy virtual fish costing $49.99 to feed virtual penguins living on virtual melting ice caps. The FTC said the Internet giant had also agreed to modify its billing practices to ensure that parents know, and agree to, purchases that their children make. Google said it implemented changes in March 2014 that made it clearer when real — as opposed to virtual — money was being spent. And it said that it allowed consumers to choose whether they wanted to be prompted to enter a password with each purchase. The FTC settled a similar case with Apple in January for at least $32.5 million. The FTC sued Amazon in July on the same issue.